:root {
    --primary: #2563eb;
    --primary-hover: #1d4ed8;
    --success: #16a34a;
    --success-hover: #15803d;
    --error-bg: #fef2f2;
    --error-text: #991b1b;
    --error-border: #f87171;
    --bg-color: #f3f4f6;
    --card-bg: #ffffff;
    --text-main: #1f2937;
    --text-muted: #4b5563;
    --border-color: #e5e7eb;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-main);
    line-height: 1.5;
    padding: 20px;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
}

.container {
    background-color: var(--card-bg);
    width: 100%;
    max-width: 600px;
    padding: 2rem;
    border-radius: 16px;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
}

h1 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    text-align: center;
    color: var(--text-main);
}

.form-group {
    margin-bottom: 1.25rem;
}

label {
    display: flex;
    justify-content: space-between;
    font-weight: 600;
    font-size: 0.875rem;
    margin-bottom: 0.5rem;
    color: var(--text-main);
}

.value-display {
    color: var(--text-muted);
    font-weight: 400;
}

input[type="file"], select {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    background-color: #fff;
    transition: border-color 0.2s;
}

input[type="file"]:focus, select:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

input[type="range"] {
    width: 100%;
    margin-top: 0.5rem;
    accent-color: var(--primary);
}

button {
    width: 100%;
    padding: 0.875rem;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.2s, transform 0.1s;
}

button:active {
    transform: scale(0.98);
}

.btn-primary {
    background-color: var(--primary);
    color: white;
    margin-top: 1rem;
}

.btn-primary:hover {
    background-color: var(--primary-hover);
}

.btn-success {
    background-color: var(--success);
    color: white;
    display: none;
    margin-top: 1rem;
}

.btn-success:hover {
    background-color: var(--success-hover);
}

.progress-wrapper {
    display: none;
    margin-top: 1.5rem;
}

.progress-text {
    font-size: 0.875rem;
    color: var(--text-muted);
    margin-bottom: 0.5rem;
    text-align: center;
    font-weight: 600;
}

.progress-container {
    width: 100%;
    background-color: var(--border-color);
    border-radius: 8px;
    overflow: hidden;
    height: 10px;
}

.progress-bar {
    height: 100%;
    background-color: var(--primary);
    width: 0%;
    transition: width 0.2s ease-out;
}

.error-message {
    display: none;
    background-color: var(--error-bg);
    color: var(--error-text);
    border: 1px solid var(--error-border);
    padding: 0.75rem;
    border-radius: 8px;
    margin-bottom: 1rem;
    font-size: 0.875rem;
    text-align: center;
}

.results {
    display: none;
    margin-top: 1.5rem;
    padding: 1rem;
    background-color: #f8fafc;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 0.875rem;
}

.results-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0.5rem;
    margin-bottom: 1rem;
}

.results-grid span {
    color: var(--text-muted);
}

.results-grid strong {
    color: var(--text-main);
    display: block;
}

.preview-container {
    margin-top: 1rem;
    text-align: center;
}

.preview-container img {
    max-width: 100%;
    max-height: 400px;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    object-fit: contain;
}

@media (max-width: 480px) {
    .container { padding: 1.5rem; }
    .results-grid { grid-template-columns: 1fr; }
}